Recently, the north ushered in a wide range of cooling and large areas of snow, Hebei, Henan, Shandong and other places of snow depth of ten centimeters, climate change caused by temperature differences will have different effects on the various properties of the film, resulting in quality problems of flexible packaging products. Today, from the perspective of factory production and daily storage, the analysis of how to ensure the smooth winter of flexible packaging.
First, the impact of temperature on production
Temperature is a hard index, once there is a deviation, there may be mistakes resulting in quality accidents.
In winter, it is easy to increase the crystal point of the material, increase the corona impact, poor ink transfer, ink drying, insufficient solvent volatilization rate, compound white spots, compound bubbles, warping of the finished bag, and the peeling of the edge of the bag.
On the surface, these problems seem to happen very inexplicably, make people very headache and hate, accidentally may also occur batch quality accidents, serious losses. Why do these problems keep happening when they are so exhausting to deal with and when they are so strictly controlled according to the standard book? What is the root cause of the problem?
Temperature is too closely related to our flexible packaging processing. From the equipment point of view, the process of blowing film (salivation), printing, compounding, bag making and other processes feel obvious changes are rubber rollers: When the rubber roller is particularly hard in winter, our pressure needs to be appropriately increased, and if the pressure is too large, it is necessary to consider whether the rubber roller will slip, and the transfer rate of glue and ink will be reduced, these microscopic changes we need to deal with and solve in advance in process design and actual production.
Since the film materials, glues, inks, and solvents we use are basically chemical substances, in general, the surface activity of the material is positively correlated with temperature: the higher the temperature, the better the activity of the material, the better the activity of the material, the higher the affinity of the surface, the more active the surface activity of the material; The higher the temperature, the better the infiltration of glue and ink on the material, and at the same time, the affinity of the material for glue and ink also increases. Therefore, the performance of the composite process is particularly obvious: the same material, machine speed, it is easy to foam in winter, because the winter temperature is low, the surface activity of the material is low, that is, the inertia of the material is high, and the affinity between the glue and the material is reduced.
As the temperature changes, the temperature of the glue and ink itself will also change, and the low temperature of the glue ink will require more heat to allow the solvent to volatilize, and at high temperatures, the solvent is extremely volatile.
To sum up, the temperature change, the impact on our flexible packaging is still very great, in the production we should avoid these problems as much as possible, carefully and carefully do every link, to make stable qualified products.
Second, the impact of low temperature on finished plastic packaging
First of all, low temperature will have an impact on the mechanical properties of plastic bags. Studies have pointed out that with the decrease of temperature, the tensile strength and elongation at break of plastic bags will gradually decrease. This means that at low temperatures, plastic bags may become more fragile and vulnerable to external damage.
In addition, low temperature will also affect the weather resistance of plastic bags. In the low temperature environment, the light transmission and ultraviolet resistance of plastic bags will be reduced, resulting in shortened service life. Plastic bags that are in a low temperature environment for a long time may have cracks, cracks and other phenomena.
In addition, low temperature also has an impact on the chemical corrosion resistance of plastic bags. In the low temperature environment, the chemical corrosion resistance of plastic bags will be reduced, and it may be more vulnerable to chemical erosion.
In general, the impact of low temperature on plastic bags is mainly reflected in mechanical properties, weather resistance and chemical corrosion resistance. Therefore, in a low temperature environment, the storage of plastic bags needs to pay attention to the following points:
Avoid contact with sharp objects: When storing plastic bags, you should avoid storing them with sharp objects to avoid being scratched or punctured.
Avoid pressure: Plastic bags may be deformed or broken after pressure, so it should be placed in a flat place to avoid being squeezed or compressed.
Keep dry: Plastic bags are easy to absorb moisture, so pay attention to keep them dry when stored to avoid moisture or wet.
Avoid exposure to the sun: Plastic packaging bags exposed to the sun for a long time may age, deformation or rupture, so it should be avoided in the sun for a long time.
Classification storage: If multiple types of plastic bags are stored at the same time, they should be classified and stored to avoid confusion or pollution.
Note the use period: plastic packaging bags also have a certain use period, if expired or aging, should be replaced or treated in time, so as not to affect the packaging effect or cause environmental pollution.
